For example, in a case in which processing of a work is performed via a plurality of automatic processing machines, an automatic work conveyor or the like is used for delivering the work between the automatic processing machines. In the automatic work conveyor, since there is a distance between a conveyance position at which the work is held and moved and a processing location of the automatic processing machine, a multi-jointed robot arm which performs the delivery therebetween is used. PTL 1 discloses a multi-jointed robot arm which is used in a processing device. Specifically, in a multi-jointed robot arm which runs along a rail on the top portion of a machine tool, a first arm and a second arm are joined to a robot base via a first joint and a second joint, and a robot hand is attached to the tip of the second arm via a third joint. The delivery of the work to the machine tool is performed through the operation of the joints and the robot hand.